CFR›Title 49›Subtitle B›Chapter I›Part 172›Appendix Appendix C to Part 172 CorpusDaily eCFRDisplayed edition2026-04-15Last updated2026-04-15 Appendix C to Part 172—Dimensional Specifications for Recommended Placard Holder Previous Appendix B to Part 172 Appendix B to Part 172—Trefoil Symbol Next Appendix D to Part 172 Appendix D to Part 172—Rail Risk Analysis Factors